CVE-2017-11057 in Android
Summary
by MITRE
In Android for MSM, Firefox OS for MSM, QRD Android, with all Android releases from CAF using the Linux kernel, in compatability mode, flash_data from 64-bit userspace may cause disclosure of kernel memory or a fault due to using a userspace-provided address.
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Analysis
by VulDB Data Team • 01/16/2021
This vulnerability exists in Android-based systems that utilize the Linux kernel from Code Aurora Forum with compatibility mode enabled. The flaw specifically affects 64-bit userspace applications when they invoke the flash_data function, creating a critical security risk through improper memory handling mechanisms. The vulnerability stems from insufficient validation of user-provided addresses within the kernel space, allowing potentially malicious or malformed inputs to trigger unintended behavior. When the flash_data function processes these addresses, it fails to properly sanitize or verify the memory references, leading to potential information disclosure or system instability. This represents a classic case of improper input validation and memory management in kernel-level operations.
The technical implementation of this vulnerability occurs through the interaction between userspace and kernel space memory management. When 64-bit applications execute the flash_data function, they pass addresses that should be validated before being processed by kernel components. The kernel's failure to properly validate these addresses means that arbitrary memory locations could be accessed, potentially exposing sensitive kernel memory contents to userspace applications. This memory disclosure could reveal critical system information including kernel pointers, stack contents, or other confidential data that could be leveraged for further exploitation. The vulnerability is particularly concerning because it operates within the compatibility mode context, suggesting that the issue affects systems that maintain backward compatibility with older software stacks.
The operational impact of this vulnerability extends beyond simple information disclosure to potentially enable more sophisticated attacks. An attacker could exploit this flaw to gain insights into kernel memory layouts, which could be used to bypass security mitigations such as address space layout randomization or kernel stack canaries. The potential for system faults also means that this vulnerability could be weaponized for denial-of-service attacks, where an attacker could cause system crashes or instability by triggering the memory access violations. This vulnerability affects multiple Android variants including MSM, Firefox OS, and QRD Android platforms, indicating a widespread impact across various mobile device ecosystems that rely on the Linux kernel infrastructure. The compatibility mode aspect suggests that this affects devices that maintain legacy support, making it particularly dangerous for older or enterprise devices that continue to receive updates but operate with compatibility layers.
Mitigation strategies for this vulnerability should focus on implementing proper address validation mechanisms within kernel space functions. The most effective approach involves modifying the flash_data implementation to validate all user-provided addresses before processing them, ensuring that memory references fall within acceptable kernel memory regions. This aligns with common security practices outlined in CWE-125 for out-of-bounds read vulnerabilities and CWE-787 for out-of-bounds write conditions. System administrators should implement kernel patches that enforce stricter memory access controls and address validation. Additionally, this vulnerability maps to ATT&CK technique T1068 which involves exploitation of local privileges to gain system-level access, making it a critical target for defensive measures. Organizations should prioritize patching affected systems and monitoring for potential exploitation attempts, particularly in environments where mobile devices may be exposed to untrusted users or networks. The vulnerability highlights the importance of maintaining secure kernel interfaces and proper validation of all user-space inputs before they are processed in kernel contexts.